This Is MS Multiple Sclerosis Community: Knowledge & Support

Normal CSF circulation, in which there is a correct balance between ultrafiltration of CSF (from the veins of the lateral ventricles) and its clearance from the CSF space into the venous system at the level of the dural sinuses, depends on efficient venous drainage (16,24-26). Impaired CSF dynamics may be a factor contributing to the increases in 3rd ventricle and lateral ventricle volumes that we measured (Table II), and that are observed very frequently in MS patients.

Our findings, demonstrating that CCSVI has a significant impact on brain pathophysiology, and particularly on the balance of intracranial fluids, could provide stimulation for the development, in the future, of mathematical models currently lacking (probably because the de-
scription of CCSVI is so recent). A model is needed in which increased resistance of venous outflow is partially corrected by the development of collateral circulations (2,19). Speculatively, the imbalance in CSF filtration-reabsorption processes might be related to increased transmural pressure in the condition of CCSVI (1,5,23, 24). CSF flow assessment is a novel MRI tool, and it would probably be a useful parameter to measure dur-
ing the follow up of patients submitted to endovascular procedures to correct extracranial venous stenoses in CCSVI (5). It can be hypothesized that improved VHISS would correspond to coherent changes in CSF flow dynamics.